Obviously, the role of Superman is taken. Was The Rock telling fans that he's being considered — or was even already signed — for a role in a Shazam movie? And did his Tweet mean Warner would announce it in San Diego?

Rock's Tweet is just the latest in a long list of evidence that points toward a Shazam film.

In June, well-known entertainment reporter Nikki Finke cited unnamed sources to allege that a Shazam film was being planned by Warner as early as July 2016 — less than two months after the release of Batman v. Superman: Dawn of Justice.

It should be noted that, as accurate as Nikke Finke's posts usually are, even she admitted that the schedule she cited remains "in flux." And the lack of an announcement at last month's Comic-Con International in San Diego makes a summer 2016 release date questionable.

The movie, however, is looking more and more likely, particularly if DC's Chief Creative Officer Geoff Johns has any influence. When asked in mid-July about which character he'd like to see brought to live action next, Johns said "Shazam."

Johns has certainly shown the character a lot of attention in his comics, having recently revamped Shazam for the company's rebooted New 52 universe, then adding him to the roster of the best-selling title Justice League. The writer has also written the character in past incarnations, including his work on the long-running Justice Society of America and an alternate universe version of Shazam in Flashpoint.

But now that Warner seems to have pretty clear plans in place for Superman, Batman and Wonder Woman — as well as an idea of what they're doing with Justice League — could attention have shifted back to Shazam?

The project might not have been as dead as the director thought. As Johns told Newsarama in 2012, "there's always a possibility for Shazam. There's always talk about Shazam. And I can't get into the specifics on that, but yeah, there's hope for Shazam."

Movie Potential

There may be other reasons for the resurgence of Shazam at Warners — not the least of which is the success of Guardians of the Galaxy. It may be a bit of a stretch to compare the two franchises — after all, one dates all the way back to the 1940's and the other is a concept formed only a half dozen years ago.

But as Segal explained recently, humor is an important part of the Shazam movie he was helping to develop — and so is the idea of flawed characters, something that isn't as prevalent in Warner's more iconic heroes like Superman and Batman.

"There's this opportunity to play a lot of humor with the action [in Shazam]," Segal said. "These characters are flawed and, within those flaws, there is humor."

There's also potential for a younger skew with the character, because, as Johns has often said, the core of the Shazam story is "wish fulfillment" for kids, as a young Billy Batson can turn into a superhero whenever he wants.

And as Segal put it, Shazam is actually "this boy trapped inside of a superhero's body. He's still a boy inside."

That man-on-the-outside-but-boy-on-the-inside concept might explain the possible casting of Johnson in the role, since the actor's been leaning toward roles that cast him as a family film star. And Johnson's playful persona — put on display in movies like The Game Plan and Tooth Fairy — would work well with the idea of a boy's mind being inside a superhero-esque physique.

There's also precedent for kids flocking toward the Shazam concept. In the 1940s, his appearances in Captain Marvel Adventures were so popular that the comic sold an estimated 2 million copies, an impressive number for comic sales. The character, who got his powers through a wizard, was particularly compelling for young kids because it implied they could be a superhero like Billy Batson. All it took was the magic word, "Shazam!"

Multiversity #5 - Thunderworld

Credit: DC Comics

The kid-friendly appeal of the character is what's usually heightened by creative interpretations of Shazam — like author and cartoonist Jeff Smith's Shazam!: The Monster Society of Evil back in 2007, and superstar comic book writer Grant Morrison's upcoming "Pixar-like" interpretation in the highly anticipated mini-series Multiversity.

Warner's Cartoon Network just released a Shazam! short as part of its DC Nation Shorts series, pitting Billy Batson against math problems.

Could Warner have been testing the waters, or paving the way, for a live action Shazam movie? It's certainly looking that way.